In many instances it is highly desirable from an economic and convenience standpoint to be able to accurately measure the blood pressure of an individual without the use of a doctor or nurse. To this end, automatic blood pressure measuring devices have been developed, some of which involve detection of Korotkoff sounds. However, the degree of correlation between blood pressure readings taken automatically by these prior art devices and similar readings taken by a doctor is not as high as is desirable. It is well known that a blood pressure reading for an individual may vary depending on the method used to measure the blood pressure. For example, measurement of blood pressure by the use of a catheter inserted in a blood vessel may result in a significantly different reading than blood pressure measured by the standard auscultation technique. Since most diagnosis using blood pressure measurement is based on a doctor's knowledge and experience and reference material regarding blood pressure measurements taken by the standard auscultation technique, it is highly desirable to have readings from an automatic blood pressure measuring device come as close as possible to readings made by a doctor using the standard auscultation technique. Also, it is desirable to have blood pressure measurements include all information which might be needed by a doctor including indication of Phase IV as well as Phase V Korotkoff sounds. Particularly, controversy centers over whether the Phase IV of the Korotkoff sounds (the period marked by the distinct, abrupt muffling of sound) or Phase V (the point at which sounds disappear) should be utilized to determine the diastolic pressure. The American Heart Association in its 1967 report recommends that whenever possible both the Phase IV and Phase V pressures should be recorded. Therefore, it is highly desirable to have blood pressure measuring apparatus which indicates both the Phase IV and Phase V pressures, where possible.